JP2016140925A - Multi-wire electrical discharge machining apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-wire electrical discharge machining apparatus which can effectively process a wire without breaking the wire.SOLUTION: A multi-wire electrical discharge machining apparatus 1 comprises a high frequency pulse power supply unit 60 which supplies a high frequency pulse power to a wire R and an ingot I. The high frequency pulse power supply unit 60 comprises: a processing electrical power supply source 61; a power feed terminal 70 which so contacts parallel wires R as to apply electric power from the processing electrical power supply source 61 to the wires; and a connection circuit 80 which connects the processing electrical power supply source 61 and the power feed terminal 70 via a switch. The power feed terminal 70 includes a first power feed terminal 71 and a second power feed terminal 72 which contact the wires R of different rows and are insulated from each other. The connection circuit 80 has: a first circuit 81 which connects the first power feed terminal 71 and the processing electrical power supply source 61 to each other via a first switch 81a; and a second circuit 82 which connects the second power feed terminal 72 and the processing electrical power supply source 61 via a second switch 82a.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a multi-wire electric discharge machining apparatus.

  Conventionally, a wire saw using abrasive grains has been known as a cutting means for cutting a wafer from a cylindrical ingot. In this wire saw, a cutting wire wound between a plurality of guide rollers is driven at a high speed in the longitudinal direction, and the workpiece is cut and fed to the wire, whereby a large number of thin pieces are simultaneously removed from the workpiece. Cut out. The cut wafer is flattened while grinding and removing scratches generated by the wire saw, and a device is formed on the surface to become a semiconductor wafer.

  However, in such a wire saw, it is necessary to simultaneously supply a processing liquid (slurry) mixed with processing abrasive grains to a plurality of wires formed between guide rollers, and handling thereof is not easy. . In addition, since the wire is in direct contact with the workpiece, the wire may be disconnected during cutting, particularly when the workpiece is made of high hardness SiC or the like. There was an inconvenience that took a long time. Therefore, a multi-wire electric discharge machining device has been devised (Patent Document 1).

JP 2000-94221 A

  The multi-wire electric discharge machining apparatus disclosed in Patent Document 1 generates electric discharge between a wire and a workpiece by electric power applied to the wire by a high-frequency pulse, and removes a part of the workpiece to perform cutting. Since the multi-wire electric discharge machining apparatus generates electric discharges by the number of pulses, it is set so that machining proceeds faster by applying electric power with high-frequency pulses.

  However, in the multi-wire electric discharge machining apparatus, the wire is also damaged by the electric discharge. Therefore, if the frequency of the power applied to the wire is too high, the pulse interval is too short and the wire is disconnected. Therefore, the multi-wire electric discharge machining apparatus disclosed in Patent Document 1 can only apply power to the wire at a frequency that does not cause the wire to break, and it is difficult to perform machining efficiently using a high-frequency pulse generated by the power source. There was a problem of becoming.

  Therefore, the problem to be solved by the present invention is to provide a multi-wire electric discharge machining apparatus that can be efficiently machined without breaking the wire.

  In order to solve the above-described problem, a multi-wire electric discharge machining apparatus according to the present invention includes a plurality of guide rollers arranged at intervals and a plurality of turns wound at intervals in the axial direction of the guide rollers. A wire for cutting the ingot in parallel between the guide rollers, a base portion for fixing the ingot, and a high frequency pulse power supply unit for supplying high frequency pulse power to the wire and the ingot fixed to the base portion. A multi-wire electric discharge machining apparatus that performs electric discharge machining of the ingot with the wire, wherein the high-frequency pulse power supply unit parallels a machining power supply that outputs power with a high-frequency pulse and the power from the machining power supply between the guide rollers. A power supply applied in contact with the wire, a connection circuit for connecting the machining power supply and the power supply via a switch, and a control means for controlling the switch. And the supply circuit includes at least a first supply battery and a second supply battery that are in contact with different wires of the parallel wires and are insulated from each other, and the connection circuit includes: A first circuit that connects the first power supply and the machining power source via a first switch, and a second circuit that connects the second power supply and the machining power source via a second switch. And the control means sequentially opens and closes the first switch and the second switch between the pulses of the high-frequency pulse power, and the power from the processing power source is the first And the second power supply are sequentially supplied.

  In the multi-wire electric discharge machining apparatus, the switch may be constituted by a transistor.

  In the multi-wire electric discharge machining apparatus, the machining power source can adjust the frequency of the high-frequency pulse, and the timing for opening and closing the switch can be adjusted in accordance with the frequency.

  Therefore, in the multi-wire electric discharge machining apparatus of the present invention, the first switch and the second switch are sequentially opened and closed between the pulses of the high-frequency pulse power, and the wire and the first contact with the first supply electron The two wires are applied in turn to the wire that contacts the supply. Therefore, the multi-wire electric discharge machining apparatus has an effect that the power of the high-frequency pulse generated by the machining power source can be efficiently applied to the wire without increasing the local damage to the wire.

FIG. 1 is a schematic diagram illustrating a configuration example of a multi-wire electric discharge machining apparatus according to the first embodiment. FIG. 2 is a perspective view illustrating a configuration example of a cutting wire portion of the multi-wire electric discharge machining apparatus according to the first embodiment. FIG. 3 is a diagram illustrating a configuration example of a high-frequency pulse power supply unit of the multi-wire electric discharge machining apparatus according to the first embodiment. FIG. 4 is a diagram illustrating a configuration example of a machining power source of the multi-wire electric discharge machining apparatus according to the first embodiment. FIG. 5 is a diagram illustrating high-frequency pulse power output from the machining power supply of the multi-wire electric discharge machining apparatus according to the first embodiment.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the structures described below can be combined as appropriate. Various omissions, substitutions, or changes in the configuration can be made without departing from the scope of the present invention.

Embodiment 1
A multi-wire electric discharge machining apparatus according to Embodiment 1 will be described. FIG. 1 is a schematic diagram illustrating a configuration example of a multi-wire electric discharge machining apparatus according to the first embodiment. FIG. 2 is a perspective view illustrating a configuration example of a cutting wire portion of the multi-wire electric discharge machining apparatus according to the first embodiment. FIG. 3 is a diagram illustrating a configuration example of a high-frequency pulse power supply unit of the multi-wire electric discharge machining apparatus according to the first embodiment. FIG. 4 is a diagram illustrating a configuration example of a machining power source of the multi-wire electric discharge machining apparatus according to the first embodiment. FIG. 5A is a diagram illustrating high-frequency pulse power output from the machining power supply of the multi-wire electric discharge machining apparatus according to the first embodiment. FIG. 5B is a diagram illustrating the power applied to the first power supply of the multi-wire electric discharge machining apparatus according to the first embodiment. FIG. 5C is a diagram illustrating power applied to the second power supply of the multi-wire electric discharge machining apparatus according to the first embodiment.

  The multi-wire electric discharge machining apparatus 1 performs electric discharge machining of the ingot I with the wire R. As shown in FIG. 1, the feeding bobbin 20, the take-up bobbin 21, the guide roller unit 30, the wire R, and the base The base part 41 and the high frequency pulse power supply unit 60 are provided.

  A wire R, which is a metal wire such as brass, is wound around the feeding bobbin 20 by a certain amount. The feeding bobbin 20 feeds the wire R toward the guide roller unit 30. The guide roller unit 30 is disposed in the vicinity of the feeding bobbin 20 and guides the wire R fed from the feeding bobbin 20. The guide roller unit 30 is composed of a plurality of guide rollers 30a to 30j. The guide rollers 30a to 30j are formed in a columnar shape, and are arranged in parallel to each other with an interval in the direction in which the wire R travels.

  The guide rollers 30a and 30b are disposed in the vicinity of the feeding bobbin 20, wind the wire R fed by the feeding bobbin 20, and feed the wire R toward the guide rollers 30c to 30i.

  The guide rollers 30c to 30i are arranged such that the wire R is wound around the guide roller 30c to 30i so that the wire R constitutes the parallel wire portion 310 and the wire R is supported in an annular shape. For example, the guide rollers 30c, 30d, 30e, 30g, 30h, 30i of the parallel wire portion 310 support the wire R arranged in an annular shape from the inside, and the guide roller 30f is arranged in a parallel wire portion arranged in an annular shape. The wire R of 310 is disposed so as to be supported from the outside. The parallel wire section 310 winds the wire R sent out by the guide rollers 30a and 30b a plurality of times at a constant interval in the axial direction. For example, the wire R of the parallel wire portion 310 is wound eight times around the guide rollers 30c to 30i with an interval of about 0.5 mm to several mm in the axial direction.

  In the parallel wire section 310, the guide roller 30c winds the wire R sent out by the guide roller 30b and sends it out to the guide roller 30d. The guide roller 30d winds the wire R sent out by the guide roller 30c and sends it out to the guide roller 30e. The guide roller 30e winds the wire R sent out by the guide roller 30d and sends it out to the guide roller 30f. The guide roller 30f winds the wire R sent out by the guide roller 30e and sends it out to the guide roller 30g. The guide roller 30g winds the wire R sent out by the guide roller 30f and sends it out to the guide roller 30h. The guide roller 30h winds the wire R sent out by the guide roller 30g and sends it out to the guide roller 30i. The guide roller 30i winds the wire R sent out by the guide roller 30h and sends it out to the guide roller 30c. Now, the guide roller 30c-30i which comprises the parallel wire part 310 was wound around 1 round. The wire R is wound around the remaining seven turns on the guide rollers 30c to 30i of the parallel wire portion 310 with an interval of about 0.5 mm to several mm in the axial direction. The parallel wire portion 310 sends out the last wire R wound eight times to the guide roller 30j.

  The guide roller 30j is disposed in the vicinity of the take-up bobbin 21, winds the wire R sent from the parallel wire portion 310, and sends it to the take-up bobbin 21. The winding bobbin 21 winds up and collects the wire R sent out from the guide roller 30j.

  The feeding bobbin 20, the take-up bobbin 21, and the guide rollers 30a to 30j are rotationally driven by a motor (not shown). It is not necessary to drive all the guide rollers 30a to 30j. For example, the guide rollers 30a, 30b, and 30j that do not constitute the parallel wire portion 310 may be driven rollers.

  The wire R of the parallel wire portion 310 is wound around the guide rollers 30c, 30d, 30e, 30f, 30g, 30h, and 30i a plurality of times (8 times in the first embodiment) at intervals in the axial direction. The wire R of the parallel wire 310 cuts the ingot I in parallel between the guide rollers 30c, 30d, 30e, 30f, 30g, 30h, and 30i. The wire R of the parallel wire portion 310 is stretched with a certain tension along the vertical direction by a guide roller 30g and a guide roller 30h arranged with the base portion 41 interposed therebetween. Here, the vertical direction is an upward direction or a downward direction that is perpendicular to the horizontal plane. For example, the wire R stretched by the guide roller 30g and the guide roller 30h may be stretched so as to be parallel to the vertical direction, or may be stretched so as to be slightly inclined with respect to the vertical direction. Good. The wire R stretched by the guide roller 30g and the guide roller 30h and positioned in the vicinity of the base portion 41 constitutes a cutting wire portion 320 that slices the ingot I. The wire R of the cutting wire portion 320 travels upward (arrow direction Q) along the vertical direction.

  The ingot I has a cylindrical shape and is sliced into a disc shape at intervals of the wires R of the cutting wire portion 320. The ingot I is a conductive material and is formed of a hard material such as SiC or a single crystal diamond. In the present invention, the ingot I may be made of silicon or GaN (gallium nitride).

The base portion 41 located in the vicinity of the cutting wire portion 320 constitutes a support mechanism 40 that supports the ingot I. The support mechanism 40 includes a base portion 41, support pillars 42, and drive means 43. The base part 41 fixes the ingot I. Basement 41 is adhesively secured to the conductive adhesive B side I _a of the ingot I in front 41a. The ingot I is fixed to the front surface 41a of the base portion 41 so that the end surface _Ie thereof is parallel to the arrow direction Q in which the wire R of the cutting wire portion 320 travels.

  The support column 42 is formed in a rod shape, and the base portion 41 is fixed to one end. The drive means 43 moves the base part 41 fixed to the support column 42. The drive means 43 has a ball screw (not shown) extending along the horizontal direction and a drive source composed of a pulse motor or the like. The driving means 43 moves the other end of the support column 42 fixed to the nut of the ball screw along the horizontal direction, and moves the ingot I of the base portion 41 fixed to the support column 42 to the wire R of the cutting wire unit 320. Is moved along the horizontal direction (lateral direction P). The driving means 43 may move the base portion 41 so as to be parallel to the horizontal direction, or may move the base portion 41 in a direction having a slight inclination from the horizontal direction. For example, the base part 41 is moved along the horizontal direction so as to be perpendicular to the inclination of the wire R of the cutting wire part 320.

  Multi-wire electric discharge machining is performed in a working fluid F such as water or oil which is a dielectric. The ingot I fixed to the cutting wire part 320 and the base part 41 is immersed in the processing tank 50 in which the processing liquid F is stored. In the processing tank 50, the wire R of the cutting wire portion 320 immersed in the processing liquid F processes the ingot I.

  As shown in FIG. 2, a circular opening hole 52 for attaching the base portion 41 is provided in the front surface 51 of the processing tank 50. The base part 41 is inserted into the opening hole 52 of the processing tank 50, and the gap between the opening hole 52 and the base part 41 is sealed by a seal member (not shown). A base 41 is attached to the processing tank 50 so as to reciprocate.

  The processing tank 50 has an opening 53 on its upper surface, and the wire R sent out by the guide roller 30 f enters the processing tank 50 from the opening 53. The wire R that has entered the inside of the processing tank 50 is fed out of the processing tank 50 from the opening 53 by a guide roller 30 g disposed in the processing tank 50.

  The high frequency pulse power supply unit 60 supplies high frequency pulse power to the wire R and the ingot I fixed to the base portion 41. As shown in FIG. 3, the high-frequency pulse power supply unit 60 includes a machining power supply 61, a power supply 70, a connection circuit 80, and a control unit 100.

  The machining power supply 61 outputs DC power DW (shown in FIG. 5A and corresponding to high-frequency pulse power) with a high-frequency pulse. As shown in FIG. 5A, the machining power supply 61 outputs pulsed DC power DW as high-frequency pulse power at a frequency of, for example, 100 kHz to 300 kHz. In addition, the horizontal axis of FIG. 5 has shown time. Hereinafter, the pulsed DC power DW output from the machining power supply 61, that is, the frequency of the high-frequency pulsed power is described as F (Hz), and the time length of the pulsed DC power DW is described as T. In the first embodiment, the machining power supply 61 outputs pulsed DC power DW having a frequency of 181 and 8 kHz and T of 1 μsec.

  As shown in FIG. 4, the machining power supply 61 has a DC converter 63 that converts AC power supplied from a commercial power source 62 into DC power, and the DC power converted by the DC converter 63 is described above. And a converter 64 for converting the pulsed DC power DW having the frequency F into high-frequency pulse power.

  The DC converter 63 includes a coil 63a for passing AC power supplied from a commercial power source 62 and the like, a transformer 63b, a diode bridge 63d composed of four diodes 63c, and a capacitor 63e, and converts AC power to DC. Convert to electricity.

  In the converter 64, a plurality of switching circuits 64c in which a switch element 64a and a resistor 64b are connected in series are connected in parallel, and the DC power converted by the DC converter 63 is converted into high-frequency pulse power (pulsed DC power). DW). In the plurality of switching circuits 64c, the time when the switch element 64a is turned on is T, and the on / off state of the switch element 64a is synchronously switched by the control means 100 so that the on frequency becomes the frequency F described above (control). ) As the switch element 64a, a diode or a metal-oxide-semiconductor (MOS) FET (field-effect transistor) can be used. As described above, the processing power supply 61 is configured such that the switch element 64a is formed of a diode or a MOS type FET, and the on / off timing of the switch element 64a can be adjusted as appropriate. DW) frequency can be adjusted.

  The converter 64 connects the plurality of switching circuits 64c in parallel to increase the pulsed direct-current power DW to the power at which the ingot I can be discharged by the wire R. In the first embodiment, the converter 64 includes five switching circuits 64c. In the converter 64, the plus side of the converted pulsed DC power DW is connected to the base 41, the minus side is connected to the power supply 70, and the pulsed DC power DW is supplied to the wire R and the ingot I. To do.

  The power supply 70 applies power from the processing power supply 61 in contact with the wire R arranged in parallel between the guide roller rollers 30h and 30i. The power supply 70 includes at least a first power supply 71 and a second power supply 72 that are in contact with the wires R in different rows of the parallel wires R and insulated from each other. The first power supply 71 and the second power supply 72 are formed in a bar shape parallel to the axial direction of the guide rollers 30h and 30i, and are arranged in the axial direction of the guide rollers 30h and 30i, that is, in the parallel direction of the wires R. ing. The first power supply 71 and the second power supply 72 are in contact with the four rows of wires R, respectively.

  The connection circuit 80 connects the minus side of the pulsed DC power DW output from the machining power supply 61 and the power supply 70 via a switch. The connection circuit 80 includes a first circuit 81 and a second circuit 82. The first circuit 81 connects the first power supply 71 and the negative side of the pulsed DC power DW output from the machining power supply 61 via a first switch 81a as a switch. The second circuit 82 connects the second power supply 72 and the negative side of the pulsed DC power DW output from the machining power supply 61 via a second switch 82a as a switch. The first switch 81 a and the second switch 82 a are constituted by transistors whose bases are controlled by the control means 100. On / off of the first switch 81 a and the second switch 82 a is controlled by the control means 100.

  The control means 100 controls on / off of the first switch 81a and the second switch 82a. Further, the control means 100 controls the above-described components constituting the multi-electric discharge machining apparatus 1 to cause the multi-electric discharge machining apparatus 1 to perform an electric discharge machining operation on the ingot I. Specifically, the control unit 100 outputs a motor drive signal to the feeding bobbin 20, the winding bobbin 21, and the guide rollers 30a to 30j, and performs control so that the wire R is fed and wound, and the wire R is guided. Further, the control means 100 controls the drive means 43 to output a motor drive signal so that the ingot I is cut into the wire R of the cutting wire portion 320. The control means 100 outputs a control signal to the high frequency pulse power supply unit 60 to control the frequency, voltage value, output time, etc. of the high frequency pulse power (pulsed DC power DW).

  When the control means 100 outputs a control signal to the high-frequency pulse power supply unit 60 to control the frequency of the pulsed DC power DW, the switch element 64a, the first switch 81a, and the second switch 82a are turned on / off. Control. The control means 100 controls on / off of the switch element 64a of the machining power supply 61 so that the frequency of the pulsed DC power DW becomes the frequency F (Hz) described above.

  The control means 100 includes a first switch 81a and a second switch 82a between the pulsed DC power DW (ie, pulse) from the machining power supply 61 and the next pulsed DC power DW (ie, pulse). Are sequentially opened and closed, and the first switch 81a and the second switch 81a and the second switch 72 are sequentially supplied with the pulsed DC power DW from the machining power source 61. The on / off state of the second switch 82a is controlled. The control means 100 also adjusts the timing for opening and closing the first switch 81a and the second switch 82a in accordance with the frequency of the pulsed DC power DW from the machining power supply 61.

  More specifically, the control means 100 uses every other pulsed power DW of the pulsed DC power DW having the frequency F from the machining power source 61 shown in FIG. 5A (FIG. 5B). (Hereinafter referred to as “DW1”) is supplied to the first power supply 71, and every other pulsed DC power DW1 is restricted from being supplied to the second power supply 72. In this manner, on / off of the first switch 81a and the second switch 82a is controlled. Further, the control means 100 is regulated to be supplied to the first power supply 71 of the pulsed DC power DW having the frequency F from the machining power supply 61 shown in FIG. Of the first switch 81a and the second switch 82a so that the pulsed DC power DW (shown in FIG. 5C and hereinafter denoted by reference sign DW2) is supplied to the second power supply 72. Control on / off. Thus, in the cutting wire section 320, the control means 100 makes contact with the phase of the pulsed DC power DW1 supplied to the wire R with which the first supply electron 71 is in contact with the second supply electron 72. The phase of the pulsed DC power DW2 supplied to the wire R is shifted. In the first embodiment, the frequency of the pulsed DC power DW1 supplied to the first power supply 71 and the frequency of the pulsed DC power DW2 supplied to the second power supply 72 are determined by processing. This is ½ of the frequency F of the high-frequency pulse power DW output from the power supply 61.

  The control means 100 is mainly composed of an arithmetic processing unit constituted by, for example, a CPU, a microprocessor (not shown) provided with a ROM, a RAM, and the like. It is connected to operating means used when registering content information and the like.

  Next, the machining operation of the multi-wire electric discharge machining apparatus 1 will be described. First, the ingot I is fixed to the base 41, the machining liquid F is stored in the machining tank 50, the machining content information is registered by the operator, and the machining operation is started when the machining operation is instructed. To do. In the machining operation, the control means 100 of the multi-wire electric discharge machine 1 feeds the wire R from the feed bobbin 20 and guides the wire R by the guide roller unit 30, and moves the wire R of the cutting wire unit 320 upward from below the ingot I. Drive in the arrow direction Q toward The control means 100 controls the high-frequency pulse power supply unit 60 to supply pulsed DC power DW1 and DW2 to the wire R and the ingot I.

  The control unit 100 controls the driving unit 43 to move the ingot I toward the wire R of the cutting wire portion 320 and applies a voltage between the electrodes of the wire R and the ingot I. When the wire R and the ingot I approach each other, the wire R discharges the ingot I, and pulsed DC power DW1 and DW2 are supplied to the power supply 71 and 72, mainly the wire R and the base of the wire cutting unit 320. It will flow to the base part 41. When the distance between the ingot I and the wire R, which are in an insulating state in the processing liquid F, approaches several tens of μm and the insulation between the two is destroyed and discharge occurs, the ingot I is heated and melted, and further processed. When the temperature of the liquid F rises rapidly, the machining liquid F is vaporized, and the melted portion of the ingot I is scattered by volume expansion. By supplying pulsed DC power DW1 and DW2 and applying a voltage between the electrodes, the ingot I is melted and scattered by the wire R intermittently, and electric discharge machining is performed. Slice into multiple wafers.

  As described above, according to the multi-wire electric discharge machining apparatus 1 according to the first embodiment, the first switch 81a and the second switch 81b are connected between the pulsed DC power DW and the next pulsed DC power DW. The switch 82a is opened and closed in order, and the pulsed DC power DW from the machining power supply 61 is sequentially applied to the wire R that contacts the first power supply 71 and the wire R that contacts the second power supply 72. To do. For this purpose, the multi-wire electric discharge machining apparatus 1 supplies the wire R with the phase of the pulsed DC power DW1 supplied to the wire R through the first power supply 71 and the second power supply 72. The phase of the pulsed DC power DW2 is shifted.

  Thus, the multi-wire electric discharge machining apparatus 1 divides the plurality of wires R in parallel of the cutting wire portion 320 into a plurality of groups, and applies pulsed DC power DW1, DW2 with different power supply 71, 72 for each group. The phase of the pulsed DC power DW1, DW2 to be applied is shifted for each group. For this purpose, the multi-wire electric discharge machining apparatus 1 uses the pulsed DC power DW output from the machining power supply 61 with the frequency of the pulsed DC power DW1, DW2 supplied to the wire R of the cutting wire section 320. The frequency can be reduced to about ½ of the frequency, and locally increasing damage to the wire R of the cutting wire portion 320 can be suppressed.

  Accordingly, the multi-wire electric discharge machining apparatus 1 efficiently uses the pulsed DC power DW output from the machining power supply 61 without increasing the damage locally applied to the wire R of the cutting wire section 320. There is an effect that it can be applied to the wire R. In addition, the multi-wire electric discharge machining apparatus 1 can supply pulsed DC power DW1 and DW2 from a single machining power supply 61 to a plurality of power supplies 71 and 72, so that the machining power supply 61 need not be increased. . Therefore, the multi-wire electric discharge machining apparatus 1 has an effect that it is not necessary to increase the machining power supply 61 and that the machining can be efficiently performed without disconnecting the wire R.

  In the first embodiment described above, two power supply units 71 and 72 and two circuits 81 and 82 are provided. However, in the present invention, three or more of these may be provided.

DESCRIPTION OF SYMBOLS 1 Multi-wire electric discharge machine 30a-30j Guide roller 41 Base 60 High frequency pulse power supply unit 61 Processing power supply 70 Feeder 71 1st feeder 72 2nd feeder 80 Connection circuit 81 1st circuit 81a 1st circuit Switch
82 Second circuit 82a Second switch (switch)
100 Control means I Ingot R Wires DW, DW1, DW2 Pulsed direct current power (high frequency pulse power)

Claims (3)

A plurality of guide rollers arranged at intervals, a wire wound around a plurality of times in the axial direction of the guide rollers and paralleled between the guide rollers to cut the ingot, and a base for fixing the ingot A multi-wire electric discharge machining apparatus comprising: a portion; a high-frequency pulse power supply unit that supplies high-frequency pulse power to an ingot fixed to the wire and the base portion;
The high-frequency pulse power supply unit is
A machining power supply that outputs power with high-frequency pulses;
A power supply that applies power from the processing power source in contact with the wires in parallel between the guide rollers; and
A connection circuit for connecting the machining power supply and the power supply via a switch;
Control means for controlling the switch,
The power supply is
At least a first and a second supply that are in contact with different rows of wires in parallel and insulated from each other;
The connection circuit is
A first circuit connecting the first power supply and the machining power supply via a first switch;
A second circuit for connecting the second power supply and the machining power supply via a second switch;
The control means includes
The first switch and the second switch are sequentially opened and closed between the pulses of the high-frequency pulse power, and the power from the processing power supply is supplied to the first and second supply electrons. Multi-wire electric discharge machine that is supplied in order.   The multi-wire electric discharge machining apparatus according to claim 1, wherein the switch includes a transistor. The processing power source can adjust the frequency of the high-frequency pulse,
The multi-wire electric discharge machining apparatus according to claim 1 or 2, wherein a timing for opening and closing the switch is also adjusted in accordance with a frequency.

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